Well done! I really felt the plight of the rat folk. You made the "reflection" theme worked on multiple levels, too.
There were some minor mechanical/grammatical issues that were a bit distracting, and I had to go back and reread the last half to make sure I didn't miss something about the taking of the "trophy".
But your prose is strong, and the story flowed well. I liked the bit about Arima lighting the fuse of the "explosive situation" that was developing!